The present study was aimed to evaluate the anti diabetic activity of polyherbal formulation containing some bitter plant constituents like neem, methi, karela fruit, amla , jamun seeds, kavat fruit in alloxan induced diabetic rats. Diabetic wistar albino rats were treated with standard drug glibenclamide and prepared drug formulation in two different doses 100 mg and 200 mg. Hypoglycemic effect was evaluated in these rats and the efficacy of the prepared drug was compared to the standard drug glibenclamide. Prepared drug formulation was administered for 21 days in alloxan induced diabetic rats. At the end of the study period blood glucose level were statistically analyzed based on the results. Poly herbal formulation produced a significant reduction in blood glucose levels when compared with non treated diabetic rats. So the present research work was confirmed that the polyherbal formulation possess hypoglycemic effect significantly.